13-1 Climate Page 327

A. What Factors Determine Climate? 1. Climate is the long-term prevailing weather conditions at a particular place.

A. What Factors Determine Climate? 2. Factors that can affect climate include latitude, air circulation, ocean circulation, solar activity, and volcanic activity.

B. Latitude 1. Distance from the equator measured in degrees north or south of the equator.

B. Latitude 2. Equator = 0° North/South Poles = 90°

B. Latitude 3. Low Latitudes receive more solar energy.

B. Latitude 4. High Latitudes receive less solar energy at an angle.

B. Latitude 5. Hours of daylights at north/south vary: – Winter=8 hours of sunlight= 45° latitude – Nearer to poles= Summer= sun sets few hours= Winter= sun rises a few hours

C. Global Air Circulation 1. Cold air sinks because it is denser than warm air. Cold air compresses and warms.

C. Global Air Circulation 2. Warm air rises, expands, and cools.

C. Global Air Circulation 3. Warm air holds more water vapor than cold air. When Warm air cools, the water vapor may condense to precipitation.

C. Global Air Circulation 4. The amount of solar energy determines the amount of wind and precipitation created.

D. Oceanic Circulation Patterns 1. Water holds large amounts of energy as heat.

D. Oceanic Circulation Patterns 2. Water can warm or cool coast lines by moving around due to wind and/or the rotation of the earth.

D. Oceanic Circulation Patterns 3. El Niño occurs when waters near the equator in the Pacific ocean are warmer than normal.

D. Oceanic Circulation Patterns 4. La Niña occurs when waters near the equator in the Pacific ocean are cooler than normal.

E. Topography 1. mapping of surface features such as mountains and valleys.

E. Topography 2. Climate is affect by the height above sea level.

E. Topography 3. Ex: Sierra Nevada mountains: Warm air arrives to one side where it rises and cools causing precipitation. By the time it reaches the opposite side it is dry (called rain shadow).

F. Seasonal Changes in Climate 1. Seasons are caused by the tilt of the earths axis.

F. Seasonal Changes in Climate 2. The amount of sunlight that reaches a particular place on earth varies throughout the year.